Circuit breaker



Dec. 21, 1937.

W. H. FRANK cmcUIT BREKER Original Filed March 6, 1935 2 Smets-Sheet 1 Fig INVENTOR C aeww ATTORNEY.

Dec. 2l, 1937. w FRANK 2,103,070

' `CIRCUIT BREAKER Original Filed March 6, 1935 2 Sheets-Sheet 2 oFF L... LOAD OVRLOAD OFF i` )o -l INVENTOR ATTORNEY.

Patented Dec. 21, 1937 CIRCUIT BREAXEB william n. Frank, Detroit, Mien., minor to Bulldog Electric Products Company, Detroit, Mich., a corporation of West Virginia riginal application March s, 193s, serial No.' 659,714. Divided and this application January 9, 1936, Serial No. 58,439

11 Claims.

This application 'relates to circuit breakers, and is a divisional oi a prior application, Serial No. 659,714, iiled March 6, 1933.

YIn that application there is disclosed a breaker having a link 24; normally held anchored at one end by a thermal latch I 4 and movable by means of a handle-'42 over the center oi.' rotation 43 of the handle for make and break action; the mechanism is such that movement of the free end 31 1o of the link away from a spring abutment 29 thereon determines the degree of ilexure ofthe operating spring 21 of the breaker. In that application, an Vover-center arrangement of the parts is utilized and the, free end 31 of the link 24 is arranged to move circularly only, around the center 43 of the handle 42.

The principal object of the present invention is to provlde,*in a construction generally similar to that oi application Serial No. 659,714, an arrangement of parts providing a separation of link-end 31 from spring abutment 29 much greater than that which is possible in the construction of application Serial No. 659,714. This `object is attained by replacing the over-center arrangement of the parts as shown in application Serial No. 659,714 with an arrangement disclosed herein, one employing a hill and valley path for the link end 31, the path being such that link end 31 will move radially ci the handle center 43 on breaker operation, as well as circularly, with the result that link end 31 will move away from abutment 29 a distance much greater than is the case when link end r31 can move circularly only, about center 43.

For an understanding of the breaker herein disclosed, reference is had to the following description and the accompanying drawings, in

which Figs. 1 and-2 are elevation and diagrammatic vuigws, respectively, of the breaker in on posi- Figs. 3 and 4, respectively, show the parts in 011' and overload oli positions.

The breaker includes a base I 0 having a pair oi contacts il which ar to be engaged by the contacts I2 on the ends of a. resilient bridging contact arm I3.v One of the contacts VII is connected to the line and the other is connected to one leg of thethermostatic or bimetallic warping element I4, the other leg of the latter being connected to the load. Whe'n the contact arm I3 is in "on position, current ilows through contacts II and I2, contact arm I3, and warping element I4.

To the vertically moving contact arm I3 is (Cl. 20o-116) rigidly secured an upwardly projecting sliding link I5 and a downwardly projecting guide plate I6, thesebeing insulated from arm I3, as shown.

The lower end of the guideplate I6 slides between two spring jaws I 1 of the lower guide block 5 I8 iirmly fastened to baseJIl. The sides of the sliding link I5 snugly nt into an upper guide block I9 rigidly secured to a vertical front plate 2| A link 22 is pivotally`connected at 23 to a horizontal link 24 and is also slidably connected to the upper end of the link I5 through an elongated slot 25 in link I5 receiving a pin 26o! link 22. A coil compression resisting spring 21 is mounted on the right hand end of link 24 between a pin 28 thereon and the bight of a U-shaped horizontally positioned spring compression link 29, which is pivbtally connected at 3| to a pawl 32, the latter being pivotally connected bylshouldered screws 33 on its left end to front plate 2 I. As indicated, the link 24 passes freely through a slot in the bight .of link=29 and these links move as a unit around the pivot 3 I In the on position the right hand Yor free end 35 of pawl 32 is held down by a-tongue 36 of warping element I4. f.

'I'he left hand end 31 of link 24 is pivotally con- 25 f nected to an operating bell crank 38 by'afpin 39 sliding in a slot 4Ia oi the crank. 'I'he bell crank has an extension 42 forming an operating handle for the device, and is pivotally supported on the cross shaft 43 mounted in the front plate 2l.

The slot 4Ia, as contradistinguished from the corresponding slot 4I of the breaker of Serial No. 659,714, not Vonly curves arcuately on pin 43 as a center, but is much widerthan pin 39 so that it permits radial movement of pin 39 with respect to center 43. The front plate 2I is formed to provide a hill and valley edge whose valleys are numbered 2Ia and 2lb and whose hill is numbered 2Ic, the edge forming a riding surface for the roller 39a on pin 39 oi link end 31. f

:The parts just described may be operated as a simple, quick make and break switch as follows'.l Assume the parts to be in on position (Figs. 1-2). When the handle 42 lis moved clockwise the bell crank 38 rotates clockwise carrying end 31 of link 24 along with it,`thus moving links 24 and 29 together about pivot 3| clockwise. This action pulls link 24 to the left a slight degree and builds up an increased compression in coiled spring 21. All this While the link 22 and its pin 26 travel the length of the slot 25 in sliding link I5 and link I5 and arm I3 do not move. link i5 being held by the spring jaws I1 frictionally engaging guide part I6 while the lost motiony connection between the operating mechanism and the contact is taken up.

As soon as link 24 has passed over center (shaft 43), the coil spring 21 operates to move links 24 and 29 further past shaft 43 with a snap action, thus pulling contact arm |3 to its off position for quick break, slot 4|c permitting snap action movement of links' 24 and 29 independently of the handle 42 so that quick break may be effected independently of and free of the operator.

Handle 42 is so connected that it may move the sliding link |5 without the assistance of the spring 21 after having taken up the lost motion provided in slots 25 and 4|a. This permits the handle 42 to move the bridging arm '|3 positively to the oi position and permits the operator to free the contacts I2 in case they should stick and to move the vswitch positively to the ofi position, independently of the spring, in the event the spring has become broken or weakened too much to function of its own accord.

The bell crank 38 may be moved to the extreme oi position as limited by the engagement of the reset lug 44 and stop 45 on pawl 32.

Reverse movement of handle 42, to the left from the ofi position, Fig. 3, imparts a counterclockwise movement to link 24 about pin 3| to pull link 24 to the left and compress spring 21 until link 24 is past center. All this while the Contact arm does not move. When link 24 passes over center, spring 21 expands to snap the parts, and the contact arm I3, to circuit closing position.

Slot 4|a permits snap action movement of the links 24 and 29 independent of the handle 42 so that quick make is independent and free of the operator. Positive make is assured by the positive connection between handle 42 and link |5 previously described.

During normal switch operation travel of pawl 32 about its Apivot 33 is prevented by its end 35 being held by the anchorage tongue 36 of warping element I4.

For overload release warping element I4 will release pawl end 35, permitting the compression in spring 21 to tend to move link 29, and consequently pin 3|, to the left. Since link 29 is xed to pawl 32 at 3| the movement of pin 3| to the left is necessarily accompanied by an upwardmovement of pin 3|. The parts move up until they assume the position of Fig. 4, which is the overload released position with contact arm I3 raised.

All this action is independent of the handle' 42 and consequently assures a trip-free release of the breaker. K

For reset, handle 42 is rotated to the right to rotate link 24 clockwise around its pivot 3| and to cause reset lug 44 on the bell crank -to engagea lug 45 on the pawl 32 and force the pawl down until its e'nd 35 hooks under the anchorage 3B,

link 24 meanwhile having its free end 31 elevated considerably above its normal' closed position, with the result that when the reset is completed the parts are in the oli position of Fig. 3. Contact arm I3 during such reset does not move to- Wards its on position, and consequently the circuit is not closed during reset.

On switch operation, the degree of ilexing of spring 21 is responsive-to the movement of pin 39 towards and from the spring abutment 29. In order to provide considerable ilexure, it is necessary to provide considerable travel of pin 39 measured in a direction towards and away from the abutment 29. For this reason the slot 4|a is made considerably wide so that the pin 39 can move radially of the handle center 43 as wellas circularly about such center with the result that the movement of pin 39 during breaker operation and center 43 than either of the valleys and consev quently movement of the pin 39 from the lower valley 2 la towards and over the hill 2|c provides a greater movement of the pin 39 fromabutment 29 than would be the case if the path from valley 2|a to hill 2|c were truly circular with respect to the center 43.

I claim:

1. In a circuit breaker, an operating mechanism including a pivotally mounted link, anda link mounted to slide lengthwise through a part of said first mentioned link and to move therewith about the pivot thereof, a coiled spring on the second link reacting between an abutment thereon and the aforementioned part of the rst link, a bell crank pivotally mounted on its fixed pivot and having one branch formed to provide a handle and another branch pivotally connected to an end of the second link, and means causing such end to move radially of the bell crank pivot as well as circularly around the latter when the bell crank is rotated.

2.v In a circuit breaker, an operating mechanism including a pivotally mounted link, and a link mounted to slide lengthwise through a part of said rst mentioned link and to move there-- with about the pivot thereof, a coiled spring on the second link reacting between an abutment thereon and the aforementioned part of the rst link, a bell crank pivotally mounted on its xed pivot and having one branch formed to provide a handle and another branch pivotally connected to an end of the second link, by a pin and slot connection whereof the slot is circular about the bell crank pivot and is wider than the pin riding therein, and means causing such end to move radially of the bell crankpivot aswell as circularly around the latter when the bell crank is rotated. f l

3. In a circuit breaker, an operating mechanism including a pivotally mounted link, and a link mounted to slide lengthwise through a part of said rst mentioned link and to move therewith about the pivot thereof, a coiled spring on the second link reacting between an abutment thereon and the aforementioned part of the rst link, a bell crank pivotally mounted on its fixed pivot and having one branch formed to provide a handle and another branch pivotally connected to an end of the second link, and means providing a hill and valley path whereof the hill i's radially further from the bell crank pivot than the valleys for causing such end to move radially ofthe bell crank pivot as well as circularly around the latter when the bell crank is rotated.

4. In a circuit breaker, an operating mechanism including a pivotally mounted link,v and a link mounted to slide lengthwise through a part of said rst mentioned link and to move therewith about the pivot thereof, a coiled spring on the second link reacting between an abutment thereon and the aforementioned part of the rst link, a

' therein, and means .providing a hill and valley path whereof the hill is radially further from the bell crank pivot than the valleys for causing such end to move radially of the bell crank pivot as well as circularly around the latter when theA bell crank is rotated.

5. In a circuit breaker, an operating mechanism including a pivotally mounted link, and a link mounted to slide lengthwise through a part of said rst mentioned link and to move therewith about the pivot thereof, a coiled spring on the second link reacting between an abutment thereon and the aforementioned part of the first link, a bell crank pivotally mounted on its fixed pivot and having one branch formed to provide a handle and another branch pivotally connectedto an end of the second link, and means formed from the xed frame of rthe breaker which mounts the bell crank pivot providing a hill and valley path whereof the hill is radially further from the bell crank pivot than the valleys for causing such end to move radially of the bell crank pivot as well as,

circularly around the latter when the bell crank is rotated.

6. In a circuit breaker, an operating mechanism including 'a pivotally mounted link, and a link mounted to slide lengthwise through a part of said rst mentioned link and to move therewith about the pivot thereof, a coiled spring on the second link reacting between an abutment 'thereon and the aforementioned part of the first link, a bell crank pivotally mounted on its fixed pivot and having one branch formed to provide a handle and another branch pivotally connected to an end of the second link, by a pin and slot connection whereof the slot is circular about the bell crank pivot and is wider than the pin riding therein, and means formed from the fixed frame of the breaker which mounts the bell crank pivot providing a hill and valley path whereof the hill is radially further frorn the bell crank pivot than the valleys for causing such end to move radially of the bell crank pivot as well as circularly around the latter when the bell crank is rotated.

'1. In a circuit breaker, a frame, a pivotally mounted link, a pivotally mounted handle pivotally connected thereto and operable to slide the link circularly about the pivotal mounting of the handle, a contact controller connected to the link, a spring for opposing movement of the link o'ut of one position and positioned to be stressed by and on-movement of the link out of that 4position and to move the link with a snap -action into another position when so stressed and when the link has been moved partially out of the rst position and towards such other portion by the handle, and means for guiding the link, in its movement, so that it slides radially of the handle pivot when it is moved circularly about the handle pivot by the handle, the spring being so positioned that it is stressed more byvradial andircular movement of the link than by circular movement thereof alone.

8. In a circuit breaker, a frame, a pivotally mounted link, a pivotally mounted handle pivotallyconnected thereto and operable'to slide the link circularly about the pivotal mounting' of the handle, a contact controller connected to the link, a springl for opposing movement of the link out relatively connected tha of one position and positioned to be stressed by and on moveme'ntof the link out of that position and to move the link withva snap action into another position when so stressed and when the link has been moved partially out of the rst position and towards such other portion by the handie, and means on the frame for guiding the link, in its movement, so that it slides radially of the handle pivot when it is moved circularly about the handle pivot by the handle, the spring being so positioned that it is stressed more by radial and circular movement of the link than by circular movement thereof alone.

9.` In a circuit breaker, a frame, a pivotally mounted link, a pivotally mounted handle pivotally connected thereto and operable to slide the link circularly about the pivotal mounting of the handle, a contact controller connected to the link, a spring for opposing movement of the link` out of one position and positioned to be stressed by and on movement of the link out of that position and to move the link with a snap action into another position when so stressed and when the link has been moved partially out of the first position and towards such other portion by the handle, and means on the frame for guiding the link, in its movement, so that it slides radially of the handle pivot when it ismoved circularly about the handle pivot bythe handle, the spring being so positioned that it is stressed more by radial and circular movement of the link than by circular movement thereof alone, the pivotal mounting-for the link being automatically releasable on a circuit abnormality to release the link and permit the spring to move it about its pivotal connection to the handle for circuit interruption.

10. In a circuit breaker controlling mechanism, a resilient mechanism, [a movable current responsive latch so constructed and arranged that it normally engages the mechanism for holding it, the parts being so arranged relatively that the mechanism, when held by the latch, is under 1ongitudinal stress, the latch being movable on a circuit abnormality for releasing the mechanism, a rotatably mounted handle, means operatively connecting it to the mechanism, the handie being so constructed and arranged that on rotary movement thereof out of its normal position it will stress the mechanism longitudinally and move it bodily out of its normal position and towards the center of rotation of the handle so that when the handle Y is released after such movement the mechanism will tend to relieve itself of the longitudinal stress created therein by such movement of the handle with a snap action, the parts being so arranged relatively that on such stress relieving movement of the mechanism following such handle movement'and subsequent release, the mechanis'm will move bodily beyond the center of rotation of the handle and about the connection between'the mechanism and latch as a pivot, and also being so arranged relatively that on release of the latch, when the handle and mechanism are in normal position, the mechanism will tend to relieve itself of the stress that it possesses when it is held by the latch with asnap action and in so doing will move bodily about its connection to the handle as a pivot, the resilient mechanism, the handle, and the latch being lso arrang the handle connection end of the resilient mechanism moves radially of the handle center of rotation a considerable extent as well as circularly thereof when the hanand constructed and dle is rotated to rotate the resilient mechanism about its latch connection end.

11. In a circuit breaker controlling mechanism, a resilient mechanism, a movable current responsive latch so constructed and arranged that it normally engages the mechanism for, holding it, the parts being so arranged relatively that the mechanism, when held by the latch, is under longitudinal stress, the latch being movable on a circuit abnormality for releasing the mechanism, a rotatably mounted handle, means operatively connecting it to themechanism, the handle being so constructed and arranged that on rotary movement thereof out of its normal position it will stress the mechanism longitudinally and move it bodily out of its normal position and to wards the center of rotation of the handle so action, the parts being so arranged relatively that.

on such stress relieving movement of the mechanism following such handle movement and subbeyond the center of rotation of the handle and .about the connection between the mechanism and latch as a pivot, and also being so arranged relatively that on release of the latch, when the handle and mechanism are in normal position, the mechanism will tend. to relieve itself of the stress that it possesses when it is held bythe latch with a snap action and in so doing will move bodily about its connection to the handle as a pivot, the resilient mechanism, the handle, and the latch being so arranged and constructed and relatively connected that the handle connection end of the resilient mechanism moves radially of the handle center of rotation a considerable extent as well as circularly thereof when the handle is rotated to rotate the resilient mechanism about its latch connection end, there being at the handle connection end of the resilient mech anism a hill and valley means providing.,r a hill and valley path for the handle connection end of the spring means.

WILLIAM H. FRANK. 

